Specifications for cotton bale packaging materials are approved from time to time by the Joint Cotton Industry Bale Packaging Committee (JCIBPC). According to the 1992 JCIBPC specifications, approved materials for bale ties include cold rolled, high tensile steel strapping, which may employ a fixed-seal connection, a controlled-slip connection, or a keylock type connection, and steel wire conforming to ASTM A 510-82 and employing an interlocking connection or a twistlock connection.
Steel strapping ties with controlled-slip connections are exemplified in Huson U.S. Pat. No. 4,466,535 and in Urban et al. U.S. Pat. No. 4,501,356. Steel strapping ties with keylock type connections are exemplified in Lems et al. U.S. Pat. No. 4,156,385, Duenser U.S. Pat. No. 4,226,007, and Lems et al. U.S. Pat. No. 4,228,565. Steel wire ties with interlocking connections are exemplified in Bailey U.S. Pat. No. 3,949,450 and in Simich U.S. Pat. No. 4,070,733.
Typically, a cotton bale is compressed along a major axis and tends to expand primarily along the major axis, which is vertical in a context of the aforenoted specifications. Such a bale may impart tensile forces as high as 1,800 pounds on the bale ties, along the major axis. However, such a bale tends to expand minimally along its other axes, which are orthogonal to each other and to the major axis.
The 1992 JCIBPC specifications for wire ties for use on so-called Gin Standard and Gin Universal Density Bales provide that ties shall not be smaller than 9 gauge, that the breaking strength of the wire must not be less than 3,400 pounds with a joint strength of not less than 2,100 pounds with the joint placed on the tops of the bales, and that, if the joints are placed on the sides of the bales, the breaking strength of the wire must be not less than 3,200 pounds with a joint strength of not less than 3,040 pounds. These specifications apply whether the joint is provided by an interlocking connection or by a twistlock connection. Steel wire of 9 gauge has a nominal diameter of 0.1483 inch.
As explained below, this invention enables wire bale ties of a smaller gauge to be effectively used by reducing tensile forces imparted by such a bale on the joints of such bale ties.
As a matter of related interest, Martin et al. U.S. Pat. No. 3,088,397 discloses a machine for providing steel strapping with transverse corrugations as the strapping is being fed through a strapping machine, whereby each strap applied by the machine is corrugated or marcelled over its entire length. As disclosed therein, each strap thus has resiliency to permit swelling of a bundle bound by the strap, such as a paper roll or a bag.